1. Field of the Invention
This invention is directed to coating fabrics with viscous polymer solutions for use in protective apparel.
2. Description of Related Art
Although many flexible body armor constructions adequately stop ballistic projectiles, blunt trauma can still cause substantial injury or death at a given basis weight of the fabric in an article, such as a protective vest. Conventionally, stiffer layers of fabric have been used near the body to reduce blunt trauma, but this is known to significantly compromise ballistic resistance to penetration. Further, because the fabrics are uniformly impregnated with the adhesive and in order to compensate for the associated increase in basis weight, the impregnated layers are typically placed near the body to reduce blunt trauma. This adds weight to the body armor that causes a reduction in comfort.
U.S. Pat. No. 5,776,839 discloses the application of dilatant dry powders, with a typical composition consisting of carbon black, fumed silica (nano-silica), and a small amount of adhesive “glue” to ballistic fibers and fabrics.
U.S. Pat. No. 5,229,199 considered rigid composites of woven aramid fabrics coated with an adhesion modifier and imbedded in a matrix resin. The reduced friction and weakened interfaces led to improved ballistic performance. If friction is too high in a fabric, or if the matrix is too stiff, ballistic resistance is severely compromised.
U.S. Pat. No. 5,061,545 relates to composite materials in which the resin acts as a binder for the fibers, which are mostly unidirectional. These fiber arrays are sandwiched between two continuous layers of resin.
US Publication 2002/0037391 A1 addresses resin application in patches for unidirectional structure for increased flexibility.
In order to significantly reduce basis weight, improvement in ballistic penetration resistance (V50) and reduction in back face deformation (BFD) are needed. The present invention provides a means to solve this problem.